Machine for producing curved surfaces.



E. STEAD. MACHINE FOR PRODUCING CURVED SURFACES.

v APPLICATION HLD JUNE 1. 19!.5. 31,%%7,735. Pmmed Nova 2?, 191? TSHEETS-sHEET 1.

E. STEAD.

MACHINE FOR PRODUCING CURVED SURFACES.

APPLICATION. man IUNE I. 1915.

1 M71335. Patented Nov. 2?, 191?.

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1 W1 v 67 i 4 T l I 6 66 I;

v E. STEAD.

MACHINE FOR PRODUCING CURVED SURFACES.

APPLICATION FILED JUNE 1. 1915.

1 ,MVfififi. Patented Nov. 27, 1917.

1 SHEETS-SHEET 3.

E. STEAD.

MACHINE FOR PRODUCING CURVED SURFACES.

- APPLICATION FILED JUNE 1| 195- 1,%%? ?35. Patented Nov. 27, 1917.

[SHEETS-SHEET 4.

E. STEAD.

MACHINE FOR PRODUCING CURVED SURFACES.

APPLICATION FILED JUNE I, 1915. 134mm Patented Nov. 22', 1917..

I 7SHEETSSHEET 5.

#IT/VS'SES." IA, R W @M LSIEAD.

MACHlNE FOR PRODUCING CURVED SURFACES.

APPLlCATION HLED JUNE]. 1915.

iii 3 E. STEAD.

MACHINE FOR PRODUCING C URVED SURFACES. APPLICATION ElLED lLlNE 1, I915.

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Patented Nov. 27, 1917 TSHQETS-SHEET 7.

r a m I I w y ERINES'T-STEAD, O'FlBINGI-IAMTON, NEW YORK.

"MAGHINE FOR" PRODUCING GURVEDSURFAGES.

Specification of Letters'Patent.

Patented Nov. 27,1]l91l7.

Application filed June 1, 1915. Serial No. 31,532.

To all whom it may concern: A

Be it known that'I, ERNEST STEAD, atcitizen of the United :Statesof America; and a resident of Binghamton, inlthe county of Broome, in the State of New.York,-haye invented new and useful Improvements in Machines for Producing Curved Surfaces, of which the following, takenin connection with the accompanyingdrawings,.is at-full, clear, and exact description.

This invention relates tocertain improvements in ;machines for producing curved surfaces adapted to be used more particularlywin the manufacture of lens ,grinding andpolishing tools, technically known 1 as laps and mayalso be used-for cutting the curvedlsurfaces of templets and other. im-

plements.

.The, main object is to providea simple and compact machine whereby the curved surfaces of .tools of this'character may be cut-or finished with greatergprecision or. accuracy, and at the same time to render the work more expeditious, thereby increasii'ig the output and reducinglthe cost of produc- Another object is-to enable the machine to be easily and quickly adjusted. for producing curved. surfaces of diiferentmadii.

A further object is .to provide means whereby thesame machine may-be used for cutting cylindrical, spherical or toricsurfaces. y

Other objects and usessrelating-to specific the following description.

ln thedrawings Figures 1.and2,are, respectively, a top .plan anda side elevation of. a machine embodying the various features of my inven tion.

Figs. 3 and 4-are central vertical sectional views taken, respectively, on lines 33,, and 4-4, Fig.1 1. p

Figs. 5- andl6 are, respectively ahorizontalsectional view takenion line 5-5,"Fig. 2, and av verticalsectional view taken 011 line 6.6,=Fig. 1. V y i Fig. 7 is. a side elevation, partly in, sec- ..tion, .of an attachment for cutting-l cylindri- Gal: surfaces.

Fig. 8 is ayeitical sectional view of the same device-except; that 1 a .portion of the motor is broken away.

Fig. 9 is -a-horizontal sectional 'View..of

. the same device takent on line 9- 9, Fig. 7.

Fig. lOis. a face View ofian-attachment used -in connection withzthe "machine; for

cutting tor-i0. surfaces.

'Flgsmlleand 12' are, respectively, a vertical sectional \*16W,tilk611 011'111'16 .11.11,

Fig. 10, and a horizontal; sectional view, taken on line 12l2, the;-sa1ne,figure.

Fig. '13 is a detail sectional view [taken on .l111e13.e13,;.F1g. 1.

F g. 5144s -.d1agrammatic view show1ng tion-,of..those parts for cutting aconcave surface of different rradiusywhile the dotted lines above thehorizontal.line represent one positlonof thesame parts \forcutting. a convex surface o'faa ugiven radius The particularmachine ,11llustrated uvas desi gned for use in connection wltlran lorcl1- nary lathe, and forthis purpose Ava-aprovided with.a..suitable base .1 1novable along and upon-the sways *Q OffilLOlill- .narylathe bed -3 but in actual practice the entire machine will (be constructed "as a unit for the lparticularzpurpose (to which it is adapted with such ,modificationstas may parts of the machine Will-be, brought out in ,b

e necessary in. carrying out the objects without departing from the spirit thereof.

'work as ..a- -,,the surface of which is to be cut or finished on curved. lines, vthe gwork shown inF1gs. 2 and 3 beingatlap having .a-spherical convex. surface aaszfinished by my improved finishingqdevice, although it will be evident from the foregoing,description that similar laps.'foipgrinding. or polishing cylinder or toric'lenses may be finishediin qthe..same.machine in .a manner hereinafter described. r l

prising a bracket 7 having arelatively movable section 8- for receiving the shank as -9- of a cutting tool -10-, said I cutting tool being preferably made separate from the shank and adjustably held in place by a clamp 1l' on the adjacent end of said shank whereby the tool may be adjusted endwise or rotarily when necessary;

The sectlon 8 1s adjustable horizontally'in suitable ways 12' on the lower endof the bracket -7, and together with the shank -9 of the tool is held in its adjusted position by a clamping screw 13.,

as shown more clearly in Figs. 2 and 4:.

The tool 10 is adjusted to bring its holder and in the initial setting of the machine is placed coincident with said axis, or at the center of the work, after which certain other parts of the machine are adjusted to cooperatewith other parts presentlydescribed for "causing a tool to move diametrically of the work through an arc of predetermined radius to cut the surface of the work to the desired spherical form.

The bracket 7- is secured by bolts 1lto a cross head 15', which in turn is adjustably mounted upon a horizontally extending supporting arm, 16, the latter being provided with lengthwise ways -l7- along which the bracket is adjustable by means of a screw 18 and nut -19 to cured by bolts 23 to a dove-tailed plate -.-24 which .isin sliding engagement with j described.

properly position the cutting tool 10 with respect to the work, the nut 19 being secured to the cross head 15'by a bolt 20', while the adjusting screw 18 has its. ends reduced and journaled in suitable bearings 21 and 22 onthe. arm

, the outer end of the screw being angular in cross section for engagement by a suitablewrench or hand-crank by which it maybe turned.

The inner end of the arm 16 is sea similarly dove-tailed portion of a main supporting arm -25 (Fig. 4) formoving the tool-holder across the face of the work and also for causing the arm 16 with the tool-holder thereon to swing horizontally with the arm 25, as previously The arms "16- and are disposed at right'angles to each other, the arm 16 being adjustable along and upon the arm 25 by means ofa screw 26;-.and nut -7-27, which latteris secured to the plate 24r' by means of a clamping bolt -28--. Y

tool holder is journaled in suitable supporting blocks -29 and 29- to swing horizontally about an axis at right angles to and passing through the axis of the work holder at the cutting point of the tool when thelatter'is set in its initial or starting po sition, and for this purpose is providedwith a hub ,-30- journaled in'the, clamping block 29- and provided with a co-axial 1 shaft or extension 31 screwed therein cutting point or surface in a line extending diametrically through the axis of the work latter is bolted firmly tothe'block29 and j ournaled in the clamping block -29 and a superposed standard -32, which as shown more'clearly in Figs. 3 and 4c;

7 These clamping blocks 29 and 29" are connected by bolts' 33' which serve to clamp them firmly upon a supporting plate 34, constituting'a part of the main supporting frame of the machine. and ref:

erably provided with lengthwiseand transverse slots -35-' and 36-, intersecting each other at'the axis of movement of the swinging arm 25- to permitsaid axis to be properly adjusted "relatively to the axis of the work ,holder and thecutting point between the tool and work when thetool is set .in' its initial position, as previously de scribed, the bolts-33- serving to clamp The hub 80- and its extension spindle 31 constitute a relatively long bearing ard 32 to steady the action ofthe swinging arm 25 against undue vlbratory movement, and at the same tlme permit 11; to

be easily rocked in'a' horizontal planeunder the action of its'operatlng mechanism, presing of a. screw 37 havingone end journaled in a bearing 38- on .the block 29' and its other end" engaged with a stationary nut 39 on .the'plate -3 land provided with a handiwheel40 by which the screw may be turned to effect the desired adjustment to bring the axis of the 'in the blocks .29-' and "29"-[and stand- -arm' --25- into proper relation with a the axis of the work holder.

cutting tool is slidablyinterlocked with the arm 25 to rock therewith about the axis of the hub 30, aside from its lengthwise- -movement thereon, and is provided with a threaded journal bearin or hub a1 upon which is *mounted %or rotary adjustment one 'end of a: a curve regulating arm 12 which is held in place upon the journal bearing --t1-'by a -friction washer &3 and locknut 44: engaging the threaded end of said bearing. a

This arm 42 extendsyradially from the axis of the bearing 4-1 and is slidable in a suitable guide-Way -l5 which is swiveled in a head t6 to turn aboutan axis parallel with, but some distance to onesidc locking engagement with a dove-tailed =rib -t9- on an adjacent sliding block 50-. This block 50 is slidably' interlocked by means of-a dove-tailed joint with slotted gage bar 51--which is connected by a bracket '52 to the plate 34- and forms a part of the main supportingiframe,

'the' plate being supported from the base -1 by means ofcolumns l-.

The gage bar '5l-is, thereforepfixed and runs parallel with the-axis ofthe work holder and has its tront edge provided with spective axesto't'acilitate the setting of the a scale suitably calibrated, as shown inFig.

2, along which the gage block 50- is ad justabl e and is'adapted" tobe clamped-in its adjusted position by meet-screw 53.

The means for adjusting thegageblock 50consists of a screw -'5t anda nut both of which are movable in the lengthwiseslot of the gagebar 5l, the

nut 55 being secured to the block 50 by means of a bolt 56. j

The bearings -Jc1- and are provided with pendent gage points t1 and 4 5., respectively, co-axialwith their remachine after. a. prescribed formula based upon one-half the chord of an arc otprede- -termined radius in whlch the distance between the gage points '.t1 and 45" represents' the length of-one-haltof such chord when the point 4l is in the turning ZIXIS of the arm 25 and the curve regulating arm 421s at its zero aosition as determined b -the 'raduations on the gage bar '51,it being understood I that the block -.50-; is provided with a jgage mark oirits outer face movable along said graduations and registering with the -,=zero-point when the parts are set in their initial or starting positions.

It 1s now clear that 1f the parts are left lengthwise of the arm -2'5 by the rotation -0fthescrew :26 the cutting edge of the tool 10 will be moved in the same straight line radially from the center of the worktoward'the periphery, while the re- .verse operation of-the screw will cause a reversal of the movement of the tool, but in the same straight line, which would, of course, produce a ti at surface upon the work.

It is also evident that it the arm 42 is rocked on its bearing t1 from its initial zero position to or toward the dotted position below the zero line 0, Fig. 14:, and then reclamped in its adjusted position to said bearing. the movement of the arm '16, carrying said bearing along the arm -25 by the screw -26, Fig. 8, will cause the arms -16 and 25 together "with: the tool-holder to swing horizontally about the axls ot the bearing -30, which, Jill-turn, will cause the cutting edge of the tool totravel across the face of the workholder through an arc of a circle and produce a corresponding concave surfaceon the work.

()11 the other hand if the arm 42 were adjusted to the opposite side of its normal position. it would cause the tool to produce a convex surface on the work, as .Wlll be l'ierematter more fully descrlbed.

W-The calibration of the scale may be based -.upon the altitude of an arc of any selected :JIildlLlSmdIlCl. one-halt the chord of such an are as will cause the cutting tool to produce any curvature w1th1n the hmits commonly employed in making lenses for spectacles and eye-glasses. In this particxularinstance; the selected radius of the arc .is'53O mm.=having a chord length of 410 :mm. and an altitude of 4125+ min, under which conditionsthe point 45 Fig. 3 would be initially set acdistance of 205 mm. or onehalf the length of the chord from the point 41, when said point 41 v is in the vertical plane of l the axis of the work. Then by adjusting the slide.50-- a certain distance to one side or the other of its 'zero position will cause the cutting edge or any other suitable arc, radius, and length, of chord.

In the diagrammatic view shown in Fig. 14, 16- represents the selected radius; -y the chord of the arc of such radius,

a and the are through which the tool is moved when the point -45 of the bear-" ing 4l5 carrying one end of the arm, rep resented by the line -i2 is adjusted from itszero position a distance corresponding to the altitude of such arc, and the point 4l is moved along the arm, represented by the line 25-, thus causing the cutting edge or point of the tool to travel from the point l1 through the arc represented by the line 00-, it being understood that after the arm l2- has been adjusted in the manner just described about the axis of the hub 4:1- and at an angle to the arm 16-, said arms are locked in this relation by the lock nut -i l, and that the arms 16- and maintain their right angular relation through the medium of their sliding dovetailed connections as the arm -16 and adjacent end of the arm l2 attached thereto are 7 moved along the arm -25,' thereby causing said arm 25 to rock about its fixed axis, or the axis of the spindle 3l-.

In like manner, the point i5 may be adjusted to any other angle from its zero position, represented by the line 0 for causing the cutting edge of the tool to. produce either concave or convex curvatures of different radii, the concave surfaces beving produced by the adjustment of the arm --l2- to one side of the zero position, represented by the line 0-, and convex surfaces produced by the adjustment of the.

same arm to the opposite side of saidline. "Feeding meg/n8.

being cast integrally and loosely journaled upon a hub 60- on the clamping block 29-, as shown more clearly in Figs. 3 and l.

The face gear 59 is driven by a pinion 61 onthe lower end of an upri ht shaft 62 which is journaled in suita le bearings in the clamping blocks 29-: and 29 and is connected by beveled gears 63 and 64. to a countershaft 65,

the latter being journaled in suitable bearings upon the upper portion of the main supporting "frame, as shown moreclearly in Figs. 1 and 4. l

A similar countershaft 1-65"-, 1s also A journaled upon. the upper portion ofthe frame parallel with the shaft'65-, and

7 preferably at the opposite side of-the center of the machine.

In order that each of the shafts +65- and 65- mayi be rotatedin" reverse directions for, feeding the tool -10' -f back and forth across the face of; the work,;,they are, provided, respectively, with separate sets of gears 661 and 67 and 66 and -67,-loosely mounted thereon and held against endwise movement by, pins 68' revolving inannular grooves in said in the same direction indicated by arrows x, Fig. 1, by means ofa pinion -71 and opposite idler gears +'72,;the pinion 71 being secured to theshaft of a pulley -73+ which is journaled on the main supporting frame and (connected by a belt 74- to a pulley 75 on the armature shaft of an electric motor"76 as shown in Figs. 3 and 6.

in a reversedirectionfrom that of the gears *6,6 and :66 by means of a pinion jacent gears, the corresponding shafts will remain at rest, while the gears will continue to rotate in the direction indicated by the arrows. q It is now clear that if the clutch r69- is shifted into engagement with the gear 66 the shaft 65 will be rotated in the direction indicated by arrow :v-, Fig. 1, for feeding the tool 10- in one direction, and when shiftedinto engagement with the oppositegear 67+- the tool will be moved in a reverse direction to cut, the desired The nut 44 is then'loosened and the arm -4:2 swung laterally by hand to one side or the other of its zero position (accord ing to whether the surface to be cut is concave or convex) until the index mark on the plate. 50 registers with the graduation on the scale 51 corresponding to the degree of curvatureto be cut, whereupon the nut 41, is retightened to firmly lock the arm t2 to the arm 61-. r

The machine is now set in-motion which" causes the screw 26 to drawthe arm -l6 and member -a2 alongthe arm -25- which, in turn, moves, the cutting tool radially across the face of the work.

. This longitudinal movement of the'arm 4l-2,throughits relatively stationary,- but swiveled, bearing -45 causes the arms 16 and 25,, together with the cutting tool l0, to swing slowly about the axis of the bearing-30,.for the arm 25, while the tool is traveling radially across the face-of the rotating work, so that as the tool is fed upto the work at the beginning of each forward or backward movement by the hand operation of the screw 18, it will cut the work to the desired curvature as indicated on the scale 51 the adjustment of the'screw 18 being repeated as often as necessary to complete the work, or until the cutting edges of the tool reach its initially set position in the produced axis of the bearing 30. a

In cutting cylindrical surfaces, it is simply" necessary to allow the'work to remain atrest by preventing the'rotation of the workholder andsubstituting for the bracket 7 the deviceshown in Figs. 7 8 and 9, consisting of the bracket --7 adapted to be securedin place by the same bolts l4l and carrying a rotary mill cutter 1,0 of

sufficient length to cut the cylindrical sur-' face of the desired width, said cutterbeing journaled on the bracket 7- and driven also for cutting the patterns or templets used in testing the curvature of such tools and lenses.

(in the other hand, if it is desired to cut a toric surface on the work, it is simply necessary to unscrew the chuck 5 from the threaded portion of the mandrel ;P- and to substitute therefor the device shown in Figs. 11 andlil, consisting of a face plate ;l 7 adapted to be screwed upon the threaded portion of the mandrel 4 and provided with a split hub -5 for receiving and retaining theihub of the work holding chuck -5 and permitting radial adjustment thereof, after which the sides of the split hub may be tightened thereon by means of a clamping screw 5, the arm carrying the hub -5 being adjustable radially of the face plate l by means of, a screw -i-, as shown more clearly in Fig. 11, under which conditions the base 1- and all parts carried thereby would be turned atright angles to the position shown in the drawings, for which purpose, thebase is provided with extra V-grooves, Fig. 2, for receiving the ways 2-, thus bringing the arm 25 and screw -26 parallel with the axis of the mandrel l in its initial setting, while the axis of the work would be at right angles to that ofthemandrel and eccentrically disposed with reference thereto to revolve bodily about the axis of the mandrel;that is, the workwould be adjusted radially of the mandrel to bring its surface to be cut at the desired distance from the axis of revolution to correspond to the radius of one curvature at which such surface is to be'cut, and the cutting tool10 would also be adjusted to the work surface to move in an arc of different radius in the manner previously described for cutting a spherical surface. I

In setting the ,machine for cutting these toric surfaces, the scale may or may not be used, since the skilled operator would be able to determine approximately the angle of setting of the arm --12 to produce a curve of the desired radius and by readjustment could be able to produce the exact curvature required.

In other cases, it may be desired to out curved surfaces of extremely short radius not within the range of the adjustment of the arm "4:2 and it is for this purpose that I have provided the countershaft 65, gears -6(5' and -67-, and clutch -69.

Rotary motion is transmitted from the shaft 65 to a parallel shaft 78- by means of intermeshing gears 79- and from said shaft 78- to another shaft 8 0 by means ofbevelcd gears 81-, th shaft 80 being provided with a worm 82 meshing with a worm gear -83, which is secured by bolts 84 to the swinging arm 25 coaxial therewith so that when the clutch 69- is thrown into engagement with one of the gears as 66,- slow rocking movement -will be transmitted to the arm -25 through the medium of the work and gear 83, such movement being synchronized with the movement of the part -16- along the arm -25 and is somewhat similar to that produced by the engagement of the arm -4c2- in the bearin l5 of the structure previously descri ed, although when the worm and gear 82 and -83 are employed, the use of the arm -4:2- is dispensed with, or at least loosened on the part --fl1 by the loosening of the nut 4%-.

Under these conditions, the use of the scale on the. front face of the part 51 would be dispensed with.

What I claim is:

1. In a machine of the character described, the combination of a work holder, a rocking member movable about an axis at right angles to that of the work holder, a tool holder, a support therefor adjustable about said axis to different angles relatively to the rocking member and having an independent movement radially to said axis, means for maintaining the angular relation between said support and rocking member during such radial movement, and means for rocking said member and support as the latter is moved radially to cause the tool to travel in a curvilinear path.

2. In a machine of the character described, the combination of a work holder, a rocking member movable about an axis at right angles to and passing through the axis of the work holder, a tool holder, a support therefor adjustable about an axis parallel with that of the rocking member to different angles relatively to said member and having an independent movement radially to the first named axis, means for maintaining the adjusted angular relation between the rocking member and support during such radial movement of the support, and means for effecting the rocking movement of said member while the support for the tool holder is being moved radially to the first named axis to cause the tool to move in a curvilinear path across the face of the work.

3. In a machine of the character described, the combination with a work holder and a rotary support therefor, ofa tool holder, a support for the tool holder n1o vable about an axis in a plane at right angles to that of the support for the work holder and having an independent movement radially to its axis of movement, and means for rocking the support for the tool holder about such axis as it is moved radially thereto to cause the tool to travel in a curvilinear path across the'face-of the work.

4. In a machine -of the character described, a work holder, a tool holder, a sup port for the toolholder movable about an axis in a plane at right angles to that of the work and having an independent movement radially to such axis, power-drivenmeans for effecting such radial movement,

and additional means for rocking thesupport for the tool holder about its axis as it is moved radially thereto to cause the tool to travel in a curvilinear path acrossthe face of the work.

5. In a" machine of the character described, the combination of'a work holder, a tool holder, a support for the tool holder adjustable about an axis in a plane at right angles to that of the work and having an independent movement radially to such axis,

means for feeding the support for the toolholder radially, and additional means for rocking the tool holder support about its axis simultaneously with its radial movement to causethe tool to travel in a curvilinear path across the face of the work.

6. In a machine of the character described, the combination of a work holder, a

of said arm, and means for rocking the arm andtool holder support mounted thereon as sa d support is moved lengthwise of said arm.

7. In a machine of the character de scribed, the combination with a work holder, of a rock arm movable about an: axis in a plane at right angles to that of the Work, a tool holder, a support therefor movable lengthwise of and upon the rock arm toward and from its axis and adjustable to different angles relatively thereto,means for maintainingthe adjusted angle between the rock arm and tool holder support during the movement ofsuch support along the rock arm, a guide member turnable about an axis parallel with and at one side of the axis of the rock arm, and a cooperative guide member mounted on the support for the tool holder and movable in the first namedguide member as the support for the tool holder is moved along'the rook arm to effect the rocking of said arm as the support for the tool holder is moved lengthwise thereof, thereby causing the tool to move in a curvilinear path across the face of the work.

8. In a machine of the character described, the combination of a work-holder, a tool-holder movable about an axis at right angles to that of the work-holder and having an independent movement radial to said axis, means for producing such radial movement, and additional means for gradually turning the first-named means about said axis while the tool-holder is being moved radially thereto.

9. In a machine of the character described, the combination of a rotary workholder, a swinging member movable about an axis radial to that of the work-holder and provided with a radially extending guide, a tool-holder, and supporting means therefor including a member movable along said guide and also rotatable therewith about its axis, means for moving said member along the guide, and additional means actuated by said member when moving along the guide for rocking said guide about its axis.

In witness whereof I have hereunto set my hand this 20th day of May 1915.

ERNEST STEAD.

Witnesses:

CARL F. JoHNsoN, THOMAS E. DILLON.

Uopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

